This relates generally to planetary scale object rendering. As used herein, planetary scale object rendering involves rendering objects of at least 100,000 times difference in scale.
With planetary object rendering, used, for example, in Google Earth, a user may view the entire Earth and see one level of resolution and then may, effectively, zoom in to a particular region on the Earth and see a greater resolution with respect to the smaller area. Thus, Google Earth allows users to select particular regions to view, how much of those regions to view, and thereby the system determines the resolution that the user may see.
Planetary viewers may provide convenient platforms for visualizing various scientific data, as well as for personal, social, and mass media. Planetary viewers may also be used in navigation, eco-management, geographical oversight and planning, environmental science, emergency planning and response, as well as for entertainment.
Rendering a planetary scale object, such as the Earth, with high precision in real time is challenging for 3D geometry processing due to the large variations in viewing distance and viewing area and the need for real time retrieval of a very large amount of two dimensional data, including surface elevation data. For example, a planetary viewer may view regions as close as one meter and as far as tens of thousands of kilometers, with viewing areas as small as one square meter and as large as the entire hemisphere.